An assisted-steering mechanism usually comprises an electric assistance motor and a worm mounted on an output shaft of the said motor and meshing with a toothed wheel for example fixed to the shaft of the steering column or connected to the steering rack via an intermediate pinion.
U.S. Pat. No. 6,763,738 B1 discloses an assisted-steering mechanism for a motor vehicle comprising means for adjusting the distance separating the axes of the worm and of the associated toothed wheel so as to be able to adjust the clearance that exists between the teeth of the gear during assembly.
This assisted-steering mechanism comprises no means to limit the phenomena of wear of the gear set over time.